User interface for a portion of a display screen



The FIGURE is a front view of a user interface for a portion of a display screen showing the new design.

The broken line drawing of a portion of a rectangle is for illustrative purposes only and forms no part of the claimed design. The four (4) broken line square regions and the unshaded areas there within form no part of claimed design. The broken line on the left edge of the claimed area represents an unclaimed boundary of the design. The broken line showing of the display screen is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a user interface for a portion of a display screen, as shown and described. 